def fun(a,b,c):
    if a<=0 or b<=0 or c<=0:
        print('边长不能为负数或0')
    elif a+b>c and a+c>b and b+c>a:
        print(f'a:{a} b:{b} c:{c}可以构成三角形')
    else:
        raise Exception (f'a:{a} b:{b} c:{c}不可以构成三角形')
if __name__ == '__main__':
    try:
        a = int(input('a'))
        b = int(input('b'))
        c = int(input('c'))
        fun(a,b,c)
    except Exception as e:
        print(e)



